In the art of metal forming and, as an example, the art of metal container forming, material is fed into a reciprocating press, either in sheet form or from a coil. The press reciprocates and tooling carried by the upper and lower members of the press cooperate to stamp or blank out and subsequently form various articles from the sheet of material which is usually metal and, especially in the container industry, quite thin on the order of 0.010" thick.
One of the continuing goals in the industry is to reduce the metal thickness so far as possible for economic reasons. Another object common to the industry is to increase speed and to thus obtain more finished products for each cycle of the press. Finally, the presses, particularly, again, in the container industry, have multiple sets of tooling, and these are disposed so as to make maximum use of the material, leaving only a very minimal amount of unused material. The result is to form a sheet of scrap which is sometimes referred to as a "skeleton" which is a very flimsy piece of material having a plurality of holes in it and consisting of extremely narrow interconnecting pieces of material.
This material is moved through the press during operations at relatively high speeds, of course, and ultimately exits at one end. As is common in the prior art, the material is then cut for further disposition, such as recycling or disposal.
As described more specifically in the following specification, the prior art generally includes a cutter blade on the reciprocating ram and a complemental cutter edge mounted on the base. The ram, as it reciprocates and forms the material, also cuts the scrap into pieces as the end of the sheet exits the press. Opposite the ram-mounted cutter is, conventionally, a backup member which is spring mounted and, in the prior art, as the press reciprocates, this member is depressed as the cutter comes down and springs back to its original position under the force of the spring. Galling often occurs as the backup member reciprocates within a bore in the press base in response to forces from the ram. This constant movement requires lubrication of the backup member as it moves up and down. Furthermore, there is a tendency to break off the head of the bolts holding the backup member after a period of use. Finally, this arrangement is subject to spring wear and ultimate failure.
The current solution to problems caused by the damage or failure of the components of the backup member above noted is to virtually disassemble the top portion of the base in order to replace the backup member or the failed component.
Accordingly, it is believed desirable to provide a cutter assembly which can be retrofit onto existing presses or provided as original equipment which is faster, less expensive and requires less or at least easier maintenance than the existing prior art.